I moved out of Aquatica a while back and am just now spring cleaning. I've got a variety of items for sale. All items are in good condition as shown in the pictures.
P/N 48454 97.5mm extension ring with lock $394 new, for sale ====> $158
P/N 18462 (48462) 39.5mm extension ring without lock $249 new, for sale ====> $100
P/N 18456 (48456) 16.5mm extension ring without lock $294 new, for sale ====> $100
P/N 18458 (48458) 63.5mm extension ring without lock $310 new, for sale ====> $100
P/N 20054 180 degree view finder $1333 new, for sale ====> $500
P/N 18484 6 inch dome shade $143 new, for sale ====> $30
P/N 18469 locking collar (adds the locking feature to the older port extensions) new $100 ====> $30
P/N 18790 Rear protective port cap $67 new, for sale ====> $30
A few years back Aquatica added an anti-rotation lock to their extensions. Newer (with lock) extensions begin with the number "4". Older extensions (otherwise the same) do not have the lock and begin with "1". One of my extensions has the lock. The other (1XXXX series) do not have the lock, but I've listed the otherwise equivalent 4XXXX series number as a convenience in determining "equivalent" part numbers. I've also listed a port locking collar, which was made to add the locking feature to any of the older series extensions.
There is also an 180 degree view finder. The view finder is in excellent condition optically, with some wear (as shown) on the outside.
Also listed is a 6 inch dome shade, if you'd like to have a spare.
I never had any issue with rotation, so the locks were never an issue for me but, your mileage may vary. I think Aquatica added the lock feature, primarily, due to competitive pressure rather than need.
Payments via PayPal, free shipping in the US, buyer pays shipping outside US.